Workshop do Projeto ARGO – Junho/2001

IRISA, Campus de Beaulieu, Rennes/France

{..., hurfin, ..., tronel}...

Group­based computing is becoming more and more popular when one has to design a middleware able to support reliable distributed applications. This paradigm is made of two basic services, namely, a group membership service and a group communication service. More generally, a group is a set of processes cooperating to carry out a common task (e.g., copies of a replicated server, participants in a transaction or users in a cscw­based application). Due to the desire of new processes to join the group, to the desire of a group member to leave it, or to process crashes, the composition of a group can evolve dynamically. The set of processes that currently implements the group is called the current view of the group.

This work addresses the specification and the implementation of a primary component group membership service. "Primary component" means that the specification imposes to have a single view at any time. The work first proposes a specification for the problem. Then it presents a protocol that implements that specification in asynchronous distributed systems equipped with failure detectors. This primary component group membership protocol is obtained as an appropriate instantiation of a general agreement framework [1]. Clever instantiations of the framework parameters have been investigated in order to obtain views of good quality (approximate the real membership of the group) [2].

[1] M. Hurfin, R. Macêdo, M. Raynal, F. Tronel. A General Framework to Solve Agreement Problems. In Proc. 18th IEEE Symp. on Reliable Distributed Systems ­ SRDS, pp. 56­65, 1999.

[2] F. Greve, M. Hurfin, M. Raynal, F. Tronel. Primary Component Asynchronous Group Membership as an Instance of a Generic Agreement Framework. ISADS'2001: 5th International Symposium on Autonomous Decentralized Systems, pp 93­100, March 2001.